It is the first known case of Internet addiction involving Google Glass, a fledgling technology which provides online access via a tiny screen attached to a spectacle frame, they said.

The naval serviceman had a history of drinking, depressive moods and relationship difficulties, according to the case study reported in the journal Addictive Behaviors.

He was admitted to the US Navy's Substance Abuse Recovery Programme (SARP) in San Diego, California, in September 2013 after resuming heavy drinking.

"The patient had been wearing the Google Glass device each day for up to 18 hours for two months prior to admission, removing the device during sleep and bathing," the paper says.

"He noted that when he dreamed during his residential treatment, he envisioned the dream through the device.

"He would experience the dream through a small grey window, which was consistent with what he saw when wearing the device while awake."

His superiors had allowed the man to use the device for his job as it sped up his work of identifying and logging convoy vehicles.

The gadget also helped him socially, as a topic of conversation with strangers.

The serviceman developed a dependence on the device, and without it "he was less confident and exhibited significant craving similar to patients desiring their substance of abuse," the study said.

Examined on admission, the patient repeatedly raised his right hand to his temple to tap it with his forefinger – an almost involuntary motion that he had used to turn on Google Glass and gain access to the Internet.

During the admission interview, the man's short-term memory was poor, he often lost his train of thought and rarely made eye contact, doctors found.

Under the facility's rules, patients have to give up computers and mobile phones during treatment - something that caused the patient much frustration and annoyance.

"He stated, 'The withdrawal from this is much worse than the withdrawal I went through from alcohol'," the study reported.

After his 35-day treatment, the patient became less irritable, the tapping of his temple became less frequent and his thought process and short-term memory improved.